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3 years ago

1. A train is moving north at 5 m/s on a straight track. The engine is causing it to accelerate northward at 2 m/s^2.

Physics

1 answer:

cricket20 [7]3 years ago

3 0

Answer:

It will go up to 93.75 m before it is moving at 20 m/s

Explanation:

As we know that

$v^2 - u^2 = 2aS$

here v is the final speed i.e 20 m/s

u is the initial speed i.e 5 m/s

a is the acceleration due to gravity i.e 2 m/s^2

Substituting the given values in above equation, we get -

$20^2 - 5^2 = 2*2*S\\S = 93.75$ meters

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The power rating of a 400-ΩΩ resistor is 0.800 W.

sashaice [31]

Answer:

voltage= 17.88volts

current= 0.04 amps

Explanation:

Step one:

given data

resistance R=400 ohms

Power P= 0.8W

a. What is the maximum voltage that can be applied across this resistor without damaging it?

the expression relating power and voltage is

P=V^2/R

substituting we have

0.8=V^2/400

V^2=0.8*400

V^2=320

V=√320

V=17.88 volts

the maximum voltage is 17.88volts

b.What is the maximum current it can draw?

we know that from Ohm' law

V=IR

17.88=I*400

I=17.88/400

I=0.04amps

3 0

3 years ago

As a fish jumps vertically out of the water, assume that only two significant forces act on it: an upward force F exerted by the

Sever21 [200]

Answer:

$a = 12.32 \ m/s^2$

$F = 1017.52 \ N$

Explanation:

From the question we are told that

The length of the Chinook salmon is $l = 1.50 \ m$

The mass of the Chinook salmon is $m = 46.0 \ kg$

The upward velocity in water is $u = 3.00 \ m/s$

The upward velocity in air is $v = 5.80 \ m/s$

Generally from kinematic equations

$v^2 = u^2 + 2as$

=> $5.80^2 = 3.00^2 + 2 * a * [ [\frac{2}{3} * l ]$

=> $5.80^2 = 3.00^2 + 2 * a * [ [\frac{2}{3} * 1.5 ]$

=> $5.80^2 = 3.00^2 + 2 * a * [1 ]$

=> $a = 12.32 \ m/s^2$

Generally magnitude of the force F during this interval in N is mathematically represented as

$F = m (a + g )$

=> $F = 46.0 (12.32 + 9.8 )$

=> $F = 1017.52 \ N$

5 0

4 years ago

A 6.00-kg crate is suspended from the end of a short vertical rope of negligible mass. An upward force F(t) is applied to the en

timofeeve [1]

Answer:

The magnitude of F when t=4 s=146.64 N

Explanation:

We are given that

Mass of crate,m=6.00 kg

Height of crate above its initial position is given by

$y(t)=(2.80 m/s)t+(0.610 m/s^3)t^3$

We have to find the magnitude of F when t=4.00 s

Differentiate w.r.t t

$\frac{dy}{dt]=2.8+3(0.61)t^2$

$\frac{d^2y}{dt^2}=6(0.61)t$

$a(t)=\frac{d^2y}{dt^2}=6(0.61)t m/s$

$a(4)=6(0.61)(4)=14.64 m/s^2$

Now, magnitude of force

$F=m(a+g)=6(14.64+9.8)=146.64N$

Hence, the magnitude of F when t=4 s=146.64 N

4 0

3 years ago

A truck is carrying a refrigerator as shown in the figure. The height of the refrigerator is 158.0 cm, the width is 60.0 cm. The

aliina [53]

The maximum acceleration the truck can have so that the refrigerator does not tip over is 1.86m/s².

<h3>What is acceleration?</h3>

Acceleration is the change in velocity with time.

The maximum acceleration is obtained by taking moments about the tipping point of rotation.

Moment = force * perpendicular distance
Clockwise moment = Anticlockwise moment

F₂ * 1.58 m = F₁ * 0.67 m

where

F₂ is tipping force = mass * acceleration, a

F₁ is weight = mass * acceleration due to gravity, g

The weight acts at a distance half the width of the refrigerator = 30 cm or 0.3 m

Height of refrigerator is 158 cm 0r 1.58 cm

m * a * 1.58 = m * 9.81 * 0.30

a = 1.86 m/s²

The maximum acceleration the truck can have so that the refrigerator does not tip over is 1.86m/s².

In conclusion, if the maximum acceleration is exceeded, the refrigerator will tip over.

Learn more about acceleration at: brainly.com/question/14344386

#SPJ1

8 0

2 years ago

Once the merry-go-round travels at this new angular speed, with what force does the person need to hold on?.

natita [175]

For a merry go round with a radius of R=1.8 m and moment of inertia I=184 kg-m^2 is spinning with an initial angular speed of w=1.48 rad/s is mathematically given as

F= 618.9 N

<h3>What is the centripetal force?</h3>

Generally, the equation for the angular speed is mathematically given as

w = v/R

Therefore

w= 4.7/1.8

w= 2.611 rad/s

Where total momentum

Tm= 642.96 + 272.32

Tm= 915.28

and total inertia

Ti= 184 + 246.24

Ti= 430.24

In conclusion, centripetal force

F= mrw^2

F = m*R*w2^2

F = 76*1.8*2.127^2

F= 618.9 N